This invention relates to the preparation of thermosettable polyol resins and to their use in coating compositions.
U.S. Pat. No. 4,232,135 discloses a process in which a glycidyl ester of a mixture of C.sub.9-11 branched aliphatic acids is reacted at 100.degree. C. with trimethylolpropane (hereinafter "TMP") in a glycidyl/primary hydroxyl group equivalent ratio of 2:3, in the presence of a boron trifluoride etherate etherification catalyst. However, side reactions between the alcohols, the glycidyl ester, and secondary hydroxyl groups take place in the presence of this boron trifluoride etherate catalyst. With gel permeation chromatography, the product of this process has been found to contain several side products. These products have a wide molecular weight distribution and are less suitable for coating applications.
It is therefore an object of the invention to provide a process for preparing a thermosettable polyol resin suitable for use in coating applications. It is another object of the invention to provide a thermosettable polyol resin which has a narrow molecular weight distribution and excellent flow.